‘Beneath Apple DOS’ is considered one of the most important publications for the Apple II for providing deep information about Apple’s DOS. Mike Maginnis, maintainer of 6502lane.net and Apple II Scans has made the original text files public, with the help of the original author, Don Worth.

In a 6502lane’s article he tells us a bit about the process he went through to bring those files back from old diskettes. The PDF scans of the book are also available on Internet Archive as free download.